Shorter Support Structure (for 39" modules)

Components:

2   4x4 Support Posts (Length-determined by height requirements of stair
2   l'x 1' by 3/4" Treated Plywood Pads (Will be screwed to bottom
            of 4x4 with three 3" deck screws)
2   2x6   46 1/2" Cross Supports for 39" module
4   2x4 Trimmers (Length equals distance between bottom of cross
           support and plywood pad.) (Trimmers will be screwed to 4x4.)
4  3/4"-thick Treated Plywood Gussets (see drawing for dimensions)
        (Gussets will be screwed to trimmer and cross supports with seven
        screws per gusset.) use 2 l/2" screws 

Construction Notes:

1. 4x4's support the stair module, guardrails and handrail
2. A standard guardrail height of 36" can be obtained by having 34" of 4x4 extend above the stair surface. Compute the length of each 4x4 upright by measuring down from the stair surface at front of module to plywood pad on the ground and add 34" to that number.
3. The two legs are often not the same length due to uneven terrain.
4. The cross supports are an extra 1/2" long to allow space to easily set modules in place.
5. During construction, be sure that 4x4s are plumb and cross supports are horizontal before installing trimmers, gussets and bracing. Temporarily attach cross supports with screws to allow for adjustments and place bracing and gussets after all modules are in place.